• Title/Summary/Keyword: Barrier film

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Schottky barrier Thin-Film-Transistors crystallized by Excimer laser annealing and solid phase crystallization method (ELA 결정화와 SPC 결정화를 이용한 쇼트키 장벽 다결정 실리콘 박막 트랜지스터)

  • Shin, Jin-Wook;Choi, Chel-Jong;Cho, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.129-130
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    • 2008
  • Polycrystalline silicon (poly-Si) Schottky barrier thin film transistors (SB-TFT) are fabricated by erbium silicided source/drain for n-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method. The fabricated poly-Si SB-TFTs have a large on/off current ratio with a low leakage current. Moreover, the electrical characteristics of poly-Si SB TFTs are significantly improved by the additional forming gas annealing in 2 % $H_2/N_2$, because the interface trap states at the poly-Si grain boundaries and at the gate oxide/poly-Si channel decreased.

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Schottky Barrier Thin Film Transistor by using Platinum-silicided Source and Drain (플레티늄-실리사이드를 이용한 쇼트키 장벽 다결정 박막 트랜지스터)

  • Shin, Jin-Wook;Chung, Hong-Bay;Lee, Young-Hie;Cho, Won-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.6
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    • pp.462-465
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    • 2009
  • Schottky barrier thin film transistors (SB-TFT) on polycrystalline silicon(poly-Si) are fabricated by platinum silicided source/drain for p-type SB-TFT. High quality poly-Si film were obtained by crystallizing the amorphous Si film with excimer laser annealing (ELA) or solid phase crystallization (SPC) method, The fabricated poly-Si SB-TFTs showed low leakage current level and a large on/off current ratio larger than 10), Significant improvement of electrical characteristics were obtained by the additional forming gas annealing in 2% $H_2/N_2$ ambient, which is attributed to the termination of dangling bond at the poly-Si grain boundaries as well as the reduction of interface trap states at gate oxide/poly-Si channel.

Variations of Interface Potential Barrier Height and Leakage Current of (Ba, Sr)$TiO_3$ Thin Films Deposited by Sputtering Process

  • Hwang, Cheol-Seong;Lee, Byoung-Taek
    • The Korean Journal of Ceramics
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    • v.2 no.2
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    • pp.95-101
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    • 1996
  • Variations of the leakage current behaviors and interface potential barrier $({\Phi}_B)$ of rf-sputter deposited (Ba, Sr)$TiO_3$ (BST) thin films with thicknesses ranging from 20 nm to 150nm are investigated as a function of the thickness and bias voltages. The top and bottom electrodes are dc-sputter-deposited Pt films. ${\Phi}_B$ critically depends on the BST film deposition temperature, postannealing atmosphere and time after the annealing. The postannealing under $N_2$ atmosphere results in a high interface potential barrier height and low leakage current. Maintaining the BST capacitor in air for a long time reduces the ${\Phi}_B$ from about 2.4 eV to 1.6 eV due to the oxidation. ${\Phi}_B$ is not so dependent on the film thickness in this experimental range. The leakage conduction mechanism is very dependent on the BST film thickness; the 20 nm thick film shows tunneling current, 30 and 40 nm thick films show Shottky emission current.

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Effect of Recombination and Decreasing Low Current on Barrier Potential of Zinc Tin Oxide Thin-Film Transistors According to Annealing Condition

  • Oh, Teresa
    • Journal of information and communication convergence engineering
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    • v.17 no.2
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    • pp.161-165
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    • 2019
  • In this study, zinc tin oxide (ZTO) thin-film transistors are researched to observe the correlation between the barrier potential and electrical properties. Although much research has been conducted on the electronic radiation from Schottky contacts in semiconductor devices, research on electronic radiation that occurs at voltages above the threshold voltage is lacking. Furthermore, the current phenomena occurring below the threshold voltage need to be studied. Bidirectional transistors exhibit current flows below the threshold voltage, and studying the characteristics of these currents can help understand the problems associated with leakage current. A factor that affects the stability of bidirectional transistors is the potential barrier to the Schottky contact. It has been confirmed that Schottky contacts increase the efficiency of the element in semiconductor devices, by cutting off the leakage current, and that the recombination at the PN junction is closely related to the Schottky contacts. The bidirectional characteristics of the transistors are controlled by the space-charge limiting currents generated by the barrier potentials of the SiOC insulated film. Space-charge limiting currents caused by the tunneling phenomenon or quantum effect are new conduction mechanisms in semiconductors, and are different from the leakage current.

A Study on Improvement of Optical Characteristics by Packaging Methods in Three Electrode-Type Reflective Display (3전극형 반사형 디스플레이에서 패키징 방법에 의한 광특성 개선에 관한 연구)

  • Park, Sang-Hyun;Kim, Young-Cho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.3
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    • pp.170-174
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    • 2017
  • In 3 electrode reflective displays using a plastic substrate, unstable packaging induces particle clumping and optical degradation due to external air inflow and electronic ink evaporation. In this work, we fabricate 3 electrode electronic paper using glass wafer, ITO/plastic film, and ITO/glass/gas barrier film as an upper substrate after injecting electronic ink onto the lower substrate. Then, we studied its properties. After operating under stress conditions for 336 hours at $85^{\circ}C$ and 75% humidity, the reflectivity of driven e-paper panels with white color was 25.5% for the panels using glass wafer, 22.5% for plastic film including a gas barrier layer, and 16% for plastic film only. From these optical properties, we conclude that gas barrier film improves upper film isolation as a desirable packaging method.

Study on Resistivity Characteristics of Plastic ITO Film with the Multibarrier Film by the Bending Process

  • Park, Jun-Back;Lee, Yun-Gun;Hwang, Jeoung-Yeon;Seo, Dae-Shik;Park, Sung-Kyu;Moon, Dae-Gyu;Han, Jeong-In
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.493-496
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    • 2003
  • Transmittance and resistivity is investigated according to bending of ITO (indium tin oxide)film with four other multi-barrier film. Transmission data of ITO film with four ITO films showed there was about large 90% transmission above 550 nm wavelength at three multi-barrier structures. But, both -side hard coated structure showed relatively low 75% transmission above 550 nm wavelength. Also, resistivity change of four other multi-barrier film showed there was the lowest change at oneside hard coated structure. Subsequently, with result of resistivity change according to position, it was known the resistivity change of the center increased rapidly than that of the edge.

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Improvement in the negative bias stability on the water vapor permeation barriers on Hf doped $SnO_x$ thin film transistors

  • Han, Dong-Seok;Mun, Dae-Yong;Park, Jae-Hyeong;Gang, Yu-Jin;Yun, Don-Gyu;Sin, So-Ra;Park, Jong-Wan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.110.1-110.1
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    • 2012
  • Recently, advances in ZnO based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). However, the electrical performances of oxide semiconductors are significantly affected by interactions with the ambient atmosphere. Jeong et al. reported that the channel of the IGZO-TFT is very sensitive to water vapor adsorption. Thus, water vapor passivation layers are necessary for long-term current stability in the operation of the oxide-based TFTs. In the present work, $Al_2O_3$ and $TiO_2$ thin films were deposited on poly ether sulfon (PES) and $SnO_x$-based TFTs by electron cyclotron resonance atomic layer deposition (ECR-ALD). And enhancing the WVTR (water vapor transmission rate) characteristics, barrier layer structure was modified to $Al_2O_3/TiO_2$ layered structure. For example, $Al_2O_3$, $TiO_2$ single layer, $Al_2O_3/TiO_2$ double layer and $Al_2O_3/TiO_2/Al_2O_3/TiO_2$ multilayer were studied for enhancement of water vapor barrier properties. After thin film water vapor barrier deposited on PES substrate and $SnO_x$-based TFT, thin film permeation characteristics were three orders of magnitude smaller than that without water vapor barrier layer of PES substrate, stability of $SnO_x$-based TFT devices were significantly improved. Therefore, the results indicate that $Al_2O_3/TiO_2$ water vapor barrier layers are highly proper for use as a passivation layer in $SnO_x$-based TFT devices.

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Effect of Surface Film on Void Behavior in Composite Integrated Structure (표면접착필름이 복합재 일체형 구조물에서의 기공 거동에 미치는 영향)

  • Park, Dong-Cheol;Kim, Yun-Hae
    • Composites Research
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    • v.33 no.3
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    • pp.147-152
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    • 2020
  • In this study, void behavior of composite laminate by local internal pressure gradient due to structural geometry and surface film application condition was experimentally evaluated through fabrication of spar/skin integrated structure specimens. Viscosity comparison and thermal analysis for both carbon fiber prepreg and surface film were conducted and cure characteristic and rate difference were analyzed. 2 types of spar/skin integrated structural specimens were prepared based on different application condition of surface film. Subsequently, those specimens were evaluated through visual surface inspection, non-destructive and destructive inspection. In a specimen #1 with full application of surface film, low pressurized area of composite laminate created by pressure gradient of structural geometry had voids. It exhibited that voids could not be evacuated and were locked in cured laminate by the influence of pre-cured surface film with relatively faster cure rate. In a specimen #2 without surface film, it revealed that all internal voids disappeared in the cured laminate. Therefore, it is verified that surface film acts as barrier film preventing void movement and evacuation during autoclave cure.